Flyfish New Zealand’s South Island

Southflyfisher is fly fishing in the South Island of New Zealand.

Where to Fish

So you want to flyfish New Zealand’s South Island? Well, the wild backcountry rivers and clear streams flowing through the southern regions of Central Otago, Southland, Westland, Marlborough, the West Coast and Canterbury collectively provide a lifetime of dream destinations for the pursuit of healthy and large Brown Trout.

If you want to realise your dreams, here are some pointers to help you pursue happiness. But first a couple of ‘rules to live by’:

  1. Catch & release.
  2. Keep ’em wet. 
  3. Don’t share your location in person or on social media.

If you’re planning to head to New Zealand on a one-off bucket list expedition, or have visited before but not achieved what you came here for, contact the New Zealand-based hosted flyfishing travel company, Isolation Outfitters, and discuss one of their tailored New Zealand Expedition Fly Fishing adventures.

If you’ve been over here a few times and you know the ropes, but are looking for new water, then I suggest downloading the DOC topographical map, opening up Google Earth or Google Maps and settling in for a few evenings (and a few whiskies) to search road ends, river valleys and tributaries of the major river systems. You’ll be certain to discover some good places, but first check access with the Fish & Game offices or various New Zealand angling websites so you don’t get disappointed when you finally arrive at your destination. And make sure you don’t trespass private property.

When to flyfish New Zealand’s South Island?

The New Zealand trout fishing season generally runs from October 1 to April 30 on the upper South Island rivers. Some rivers further south will open from November 1 to May 31, so keep a close eye on the regulations for the current year.

Whilst November to March is our most popular period for overseas anglers, there is often excellent fishing early in the season and again in the settled autumn season (March-May). Generally, as the fishing season progresses, the rivers get lower and the fish can be harder to entice.

Late Summer Cicada Action

We enjoy great sighted nymph fishing right through the open season, but if you are a dry fly purist, consider visiting from mid-November onwards. Sporadically, we can have an exceptional Cicada season, normally from late January to the end of February, but often into a more autumnal March.

If you are specifically seeking to fish for trophy trout in excess of 4.5kg (10 lbs), consider arriving from mid-November onwards. You’ll need to do a lot of research, be very fit and used to wilderness fishing. 

If you’re stalking trophy brown trout please remember that size and quantity does vary considerably from year to year and across catchments. We conduct frequent forays into our favourite wilderness areas to appraise trophy potential. It’s clear that variations in several factors (food, climate, habitat) play a critical role in fish welfare. Your fitness, thirst for adventure, hiking ability and fishing experience will also determine where you might see and catch large wild brown trout.

The Mouse Years

The ‘mouse years’ are often spoken about in hushed tones when assessing New Zealand’s trophy trout potential, particularly in some backcountry catchments. So why are the mouse years important?

Beech trees are New Zealand’s most abundant native forest trees, and in the South Island most forests are beech forests. These trees don’t seed every year; instead they seed irregularly, perhaps every two to six years, but with no advance warning. When they do seed, it’s called ‘masting’. In beech mast years, the trees will flower in spring, produce a lot of seed ­– around 250kg per hectare (220lb per acre). The seeds ripen in March and fall until June, providing a bountiful harvest for wild mice, whose numbers subsequently swell. In turn, this provides a feast for large, predatory trout as the mice seek new territories or fall into the water. This addition to their diet can cause the fish to grow significantly.

2019 was dubbed a ‘megamast’. It was a big beech mast year – with beech trees all over the country seeding. In addition to this, our native podocarps such as Rimu and Kahikatea also seeded. These events don’t often coincide. This set up 2019/20 to be an amazing summer season, although this was all abruptly ended for anglers by the global onset of the Covid-19 coronavirus pandemic, which followed through into the 2021/21 season.

These huge fish are likely to still be in New Zealand’s backcountry rivers in the 2021/22 southern summer season. We advise to pack a couple of mouse patterns, but remember that they will also eat your typical nymph and dry so unless you’re fishing lake edges or large pools at night, stick to the mainstream nondescript flies on these behemoths.

What gear to bring?

In this section, find out about:
Fishing Licences
Fishing equipment
Weather & what to wear

Fishing Licences are essential

By law, every person who intends to go fresh water sport fishing in New Zealand must first purchase a fishing licence. Fishing Licences are issued by Fish and Game New Zealand and the license fees are deployed to advocating habitat protection, lobbying on behalf of all anglers and helping maintain our fisheries.

The Non-Resident Licence category is now a well-established requirement for anglers visiting from overseas. All non-resident visitors to New Zealand must purchase a Non Resident Licence. Please secure one before your arrival into New Zealand.

A Non-Resident is defined as a person who is neither a New Zealand citizen nor a permanent resident (more details here). A Full Season NRL covers all of New Zealand, except the Taupo fishery, and is required by anglers wishing to fish for more than 6 days or requiring a Back Country endorsement (see next paragraph for more on the BCL). For those fishing for less than 6 days, purchasing the appropriate number of 24-hour licences is a more cost-effective option unless you need a Backcountry License.

If in doubt, just buy the Full Season Non-Resident License.


Our advice is, if in doubt, just buy the Full Season Non-Resident License given its relatively low cost. This helps to support Fish and Game New Zealand as these license fees provide their funding.

A Whole Season Non-Resident Licence is required if a visiting angler wants to apply for a BackCountry Licence or a Controlled Fishery Licence. When you secure your fishing licence, you will also need to apply online for the Backcountry Licence Endorsement before you can visit some areas particularly come of the best places to flyfish New Zealand’s South Island.

Find out about the New Zealand Fishing Licence categories, to purchase your fishing licence online, or to add a Backcountry Endorsement to an existing licence, please visit Fish and Game New Zealand or drop us a message and we’ll help you out.

Fishing Techniques and Gear to Prepare

Before your arrival to flyfish New Zealand’s South Island, undertake some solid research into which techniques are likely to be required according to the time of your visit, anticipated weather and river flows, and the locations we plan to fish.

Generally you should expect to fish nymphs in size #10 down to #16 (plus some #8 and #18’s) and dry flies from size #12 down to #16 (again #8, #10 and #18’s are likely too). Your New Zealand fly fishing outfitter or registered professional fishing guides can provide a list of preferred fly patterns for you to tie or acquire.

We prefer to use a dry fly as a natural looking indicator when practical. For nymphs, often the crystal-clear mountain water masks the true water depth that the trout is sitting and tungsten beads are often necessary to get down, sometimes carrying a second small trailing nymph. We’ll be armed with a comprehensive selection of locally-preferred flies, but please bring your fly boxes and favourite patterns.

The most popular fly rod/line combination is an AFTMA #5 weight or #6 weight, dull-coloured carbon fiber rod of around 9-foot in length with a floating line in double taper or weight forward. As a guide, your rod should be in the AFTMA #5 to #7 range and between 8’ 6” and 9’ 6” in length, preferably 4 piece for ease of travelling.  Feel free to pack a #3 to #4 weight rod to use during the lower water flows of January to March. We adore the locally-designed and assembled, world class Epic Fly Rods and we use and recommend Scientific Anglers fly lines, leaders and tippets.

Floating lines are typically used and must be a dull colour such as green, olive, grey or brown. When casting up into a decent downriver breeze, often a Weight Forward line will turn over and present a heavy two-fly rig more accurately, however the choice of WF or DT is a matter of personal preference. Feel free to pack your sink-tip and full sinking lines in case the right occasion arises, but expect to solely use floating lines on sighted fish in our backcountry streams.

We fish with long leader lengths of 12 to 17 foot including a tippet normally down to 5X – 6X. We suggest packing nylon leaders that are 9 to 12 ft long, tapering down to 2X or 3X and we can refine the taper from this base, adding tippets from 3X to 5X depending upon location. River flow and depth, water clarity, fly type and the spookiness of the trout will determine our final tippet selection.

Your reel should have plenty of backing on a large arbour and make sure your fly line has no cracks and is clean.

Most anglers prefer to bring their own equipment and we do carry a range of rods and lines, plus a selection of boots and waders for anglers who don’t have the necessary gear. Please let us know in advance so we can ensure we have the right tackle set up ready for you. Good quality breathable, walkable waders are pretty important. We recommend Simms wading boots with cleats and stud, combined with Simms high quality stocking foot waders and a suitable waist belt.

Wading boots must be rubber soled as felt soles have been banned due to the risk of carry didymo spores. Please don’t try to bring in any felt soled boots as they may be confiscated by New Zealand Customs at the airport and in any case we can’t allow their use on the river.

Our warm summer quarter is from December to February inclusive with warmer days continuing well into March. Over these hotter months we typically ‘wet wade’ by replacing our stocking foot waders with dull coloured polypropylene longs under shorts or wading pants. This allows us to more easily cover the terrain and stay cooler.

Four Seasons in One Day

When planning your apparel choices, please remember that New Zealand is a small chain of sub-tropical islands in the South Pacific Ocean.  Fortunately, the summer climate in the South Island is generally agreeable so plan with sun protection in mind, but as you get further south and west, the weather can be very cold and changeable. Stay safe by planning ahead.

A few tips: a wide brimmed hat offers good sun protection and reduces glare on the water so you’ll spot more fish. Also bring a quality sunblock of Sun Protection Factor SPF50+ to protect your skin from sunburn and any subsequent discomfort. And to spot our wily trout, please ensure you pack polarised fishing glasses. They’ll protect your eyes from intense sunlight too.

Being within the ‘Roaring Forties’ (latitude of 41°-43° S), the predominant airflow is westerly and becomes strong at times. As such, the weather can change at any time (and does). Please pack warm and waterproof clothing and come prepared for intraday extremes particularly if you are fishing in mountain terrain. Much of our fishing is in rainforests that stay green from regular and heavy downpours. Please pack a high quality stowable rainproof and windproof jacket in your day bag or in your vest.

We recommend you consider outdoor clothing layering systems, such as those available from specialist hunting/fishing clothing outfitters: First Lite, Kuiu, or Stoney Creek (respected New Zealand manufacturer). Having base, mid, and insulation layers as well as a reputable windproof and waterproof outer layer will help keep you happy regardless of what weather we encounter.

Aside from weather protection (sun/wind/wet/chill), packing dull-coloured and unobtrusive clothing is critical. The New Zealand brown trout grow to trophy size by being wary, so blending into the background is an important aspect of getting onto big fish. Your registered professional fishing guide or Isolation Outfitters will send you a useful gear checklist after your booking is confirmed. There are good local outfitters that you can visit upon your arrival if you forget anything, or want to include locally made items to your gear.

Pests & Wild Animals

You’ll be pleased to read that New Zealand does not have bears or mountain lions, no snakes or even leeches to avoid. There are a couple of rare spiders that can deliver a nasty bite, but the most vicious creatures you will encounter are amongst our smallest, the dastardly New Zealand sandfly! Similar to ‘blackflies’, these are omnipresent in many of our coastal and remote wilderness areas during daylight hours. They can be almost intolerable especially at dusk, or just prior to rain, so carry and frequently apply an effective roll-on or gel insect repellent to protect against these tiny biting beasts.

Hydrocortisone cream (available as either 0.5% – 1% from pharmacies) can be helpful to take away the inevitable itch. To avoid (or at least reduce) bites, wear long sleeved shirts, Buff-style headwear and fingerless gloves. The gloves also help to protect the fish during release. Mosquitoes are less of a nuisance. They are present at night in some river systems and fortunately carry no diseases.

“New Zealand’s one saving grace – nothing big or poisonous will bite or eat you. At the top of the food chain reigns the pesky sand fly.”

Forrest McCarthy

Wasps (yellow-jackets) feed in our native beech forests and are very common from January through April. Disturbing a wasp nest is possible, but more likely, an accidental wasp or bee sting could happen at any time. If you are allergic to wasp or bee stings, please carry suitable medication on you at all times and advise your guide and fishing companions.

On that note, please be aware that as we operate in remote wilderness areas, far from professional medical assistance, we routinely carry satellite-connected Iridium Extreme phone handsets with GPS and messaging capability to arrange urgent assistance in the unlikely event of a major accident or medical emergency.

If you’re heading into the hills on your own, without a guide, you might look to pick up a Garmin InReach Mini or similar device to keep in touch with loved ones, as well as the vitally necessary PLB which you should clip to your outer garments for easy access. These devices can save your life. You are highly unlikely to have any cellular coverage deep in the New Zealand backcountry.

Make sure to pack any prescribed medication and keep your guide or fishing companion informed if you are suffering any ailments. Finally, don’t forget your camera and/or a GoPro to capture the bucket list images!